October 27, 2010: Karl Rove's American Crossroads has drawn a lot of attention for its high-profile fundraising and lavish spending on congressional races. But Rove's group, it turns out, isn't the only one at the plate. A detailed analysis of campaign spending by cloak-and-dagger "shadow groups" — who are able to shift vast sums of money into campaign advertising and affect the outcome of competitive races — show that the groups collectively have spent nearly a quarter of a billion dollars in the 2010 cycle.

Money has already ruled the roost in American politics for years. But a recent Supreme Court decision, Citizens United, cleared the way for independent special interests groups to raise unlimited amounts of cash from companies, unions and individuals to run ads expressly supporting or opposing federal candidates for office.

So far this year, according to an ABC News report Wednesday, more than 230 independent groups have shelled out at least $227 million in 2010 federal election spending.

"We're talking about a new kind of spending," Taylor Lincoln of Public Citizen, told ABC News for a story Wednesday. "There are probably a lot of corporate spenders out there that, for fear for their reputation and a sense of what was right and the law of the land, didn't want to play that game. Now they don't have to fear any kind of legal retribution. That's a big deal."

ABC's Avni Patel cites, for example, the First Amendment Alliance, a shadowy group funded "largely by oil and gas interests:"